What frequency tones are transmitted as primary alarm signals in GMDSS?

In the Global Maritime Distress and Safety System (GMDSS), the primary alarm signals are transmitted at specific frequencies to ensure clarity and consistency across distress communications. The correct frequencies are 2200 Hz and 1300 Hz. These tones are standardized because they are easily distinguishable from other sounds and can effectively alert crew members to distress situations, thus enabling an immediate response to emergencies.

The choice of 2200 Hz and 1300 Hz specifically supports their effectiveness as alarm signals, as they are within a frequency range that is noticeable even in noisy environments, such as on a ship at sea. This high-frequency range is chosen because it can penetrate ambient noise better than lower frequencies.

Understanding the significance of these specific frequencies in the context of maritime safety highlights the importance of standardized communication protocols in enhancing the safety and efficiency of search and rescue operations on the water.